body{
    display: flex;
    flex-direction: column;
    
    // 主体
    main{
        flex-grow: 1;
        height: 1px;
    }
    
    // 底部导航
    .tabbar{
        display: flex;
        justify-content:space-around;
        align-items: center;
        width: 100%;
        height: 70px;
        font-size: 16px;
        text-align: center;
        box-shadow: 0 2px 5px 2px #666;
    
        a{
            color: #666;
    
            &.active{
                color: #4b99ff;
            }
        }
    
        i{
            display: block;
            font-size: 24px;
        }
    }
}
